Method for fabricating SONOS a memory

1. A method for fabricating a SONOS memory, comprising: providing a semiconductor substrate; forming a SONOS memory cell on the semiconductor substrate; depositing a passivation layer on the SONOS memory cell; forming a contact pad in the opening of the passivation layer; performing a first ultraviolet treatment; and performing a first annealing process after the first ultraviolet treatment.

2. The method for fabricating a SONOS memory of claim 1 further comprising: forming a first silicon oxide layer on the semiconductor substrate; forming a silicon nitride layer on the first silicon oxide layer; forming a second silicon oxide layer on the silicon nitride layer; forming a polysilicon layer on the second silicon oxide layer; performing a pattern transfer process to form a stacked gate on the semiconductor substrate; and performing an ion implantation process to form a source/drain region in the semiconductor substrate beside the two sides of the stacked gate.

3. The method for fabricating a SONOS memory of claim 1 further comprising: forming an oxide-nitride-oxide (ONO) structure on the semiconductor substrate; performing an ion implantation process to form a source/drain region in the semiconductor substrate beside the two sides of the ONO structure; forming a polysilicon layer on the ONO structure; and performing a pattern transfer process to form a stacked gate on the semiconductor substrate.

4. The method for fabricating a SONOS memory of claim 1 further comprising forming an inter-layer dielectric on the SONOS memory cell after forming the passivation layer.

5. The method for fabricating a SONOS memory of claim 4 further comprising forming a plurality of contact plugs in the inter-layer dielectric.

6. The method for fabricating a SONOS memory of claim 5 further comprising performing a metal interconnection process for forming a plurality of inter-metal dielectric and metal interconnects on the inter-layer dielectric.

7. The method for fabricating a SONOS memory of claim 1 , wherein the step of forming the contact pad further comprises: forming a top patterned metal layer; forming the passivation layer on the top patterned metal layer; forming a patterned photoresist on the passivation layer; and performing an etching process to form an opening in the passivation layer for exposing the top patterned metal layer.

8. The method for fabricating a SONOS memory of claim 7 , wherein the top patterned metal layer comprises copper, aluminum or alloy thereof.

9. The method for fabricating a SONOS memory of claim 1 , wherein the power of the first ultraviolet treatment is between 20 mW to 40 mW.

10. The method for fabricating a SONOS memory of claim 1 , wherein the wavelength of the first ultraviolet treatment is about 250 nm.

11. The method for fabricating a SONOS memory of claim 1 further comprising performing a second ultraviolet treatment after forming the passivation layer.

12. The method for fabricating a SONOS memory of claim 11 , wherein the power of the second ultraviolet treatment is between 20 mW to 40 mW.

13. The method for fabricating a SONOS memory of claim 11 , wherein the wavelength of the second ultraviolet treatment is about 250 nm.

14. The method for fabricating a SONOS memory of claim 1 , wherein the temperature of the first annealing process is between 250° C. to 410° C.

15. The method for fabricating a SONOS memory of claim 1 , wherein the duration of the first annealing process is about 2 hours.

16. The method for fabricating a SONOS memory of claim 1 further comprising performing a second annealing process after performing the first annealing process.

17. The method for fabricating a SONOS memory of claim 1 further comprising performing a second ultraviolet treatment and a second annealing process after performing the first annealing process.